Table 2.

Summary of standardized major-axis regression implemented in R statistical software (package smatr, function slope.com)

GroupFitted slope95% CI
All groups together1.101.05–1.16
Insects0.850.74–0.98
Bird eggs1.111.05–1.18
Adult birds1.221.03–1.44
Mammals0.900.80–1.02
Plants1.531.31–1.78
  • The function calculates a likelihood ratio to test if the slopes of the groups are different. Here, the likelihood ratio was 39.0 (P < 0.00001). The function also calculates a common slope and slopes for each group. CI, confidence interval.